Trace element analysis is ever increasing in importance. Applications to blood, urine and tissue samples are very widespread. Atomic spectroscopy is a preferred technique in many of these analyses. Usually it is applied in the single element mode although inductively coupled plasma emission spectrographs are now being utilized more for simultaneous multielement analyses. This proposal considers an alternate approach to multielement analysis, namely through generation of volatile hydrides followed by chromatography and subsequent sequential determination of the individual elements by a microwave induced plasma emission spectrometer. Alternately sequential atomic absorption spectrometry may serve as the determining step. Elements of both essential and toxicological significance such as Se, As. Sb, Su, and Ge will be studied. Hydride generation for these elements and others such as Pb, Bi, and Te has significant advantages over other methods including furnace atomic absorption spectrometry or any of the techniques which require solution aspiration. These advantages include relative freedom from matrix interferences, detection at Sub-ppb levels, wide dynamic linear ranges, as well as potential for sequential multielement analysis; this potential will be thoroughly investigated in the proposed work. Sequential multielement analysis can be accomplished through computer control of an atomic spectrometer for slewing and data acquisition. Samples will include blood and other biological fluids; however, the emphasis will be on freeze dried human lung tissue.